IL4 and colitis: Previously, Duan et al. has reported that the use of IL-33 ameliorated DSS induced colitis in mice by promoting regulatory T-cell responses24, while Pushparaj et al. demonstrated IL-33 exacerbated acute colitis via IL-4 in mice25; Zhu et al. simultaneously reported that IL-33 aggravated or alleviated DSS-induced acute colitis in mouse colon lamina propria by enhancing Th2 cell responses26 or by suppressing Th17 cell response as well as Th1 cell response27.